Answer:
Free radicals are atoms or molecules with an odd (unpaired) number of electrons. They can be formed when oxygen interacts with certain molecules. Many free radicals are necessary for life and are used by our body's cells to kill invading bacteria.
Step-by-step explanation:
A balance between free radicals and antioxidants is necessary for proper physiological function. If free radicals overwhelm the body's ability to regulate them, a condition known as oxidative stress ensues. Free radicals thus adversely alter lipids, proteins, and DNA and trigger a number of human diseases.